Field
Exemplary embodiments of the invention relate to a hydraulic pressure master cylinder for a bar-handle vehicle, and particularly relates to a hydraulic pressure master cylinder suitable for use in a front wheel brake of a bar-handle vehicle and a hydraulic pressure control device.
Related Art
For example, Japanese Patent No. 3542220 describes a side port type hydraulic pressure master cylinder for use in a front wheel brake of a bar-handle vehicle. A pair of cup seals is fitted to a piston. The piston is movably inserted into a cylinder hole of the hydraulic pressure master cylinder so as to define a hydraulic pressure chamber between the piston and a cylinder hole bottom portion. A relief port and a supply port are formed in a cylinder body so as to communicate with the hydraulic pressure chamber and a reservoir. When a brake is operated, the master cylinder generates a hydraulic pressure in the hydraulic pressure chamber after the cup seal disposed on the cylinder-hole-bottom-portion side closes the relief port. Also, JP 2010-64686 A describes a center port type hydraulic pressure master cylinder. A cup seal is fitted to a piston. The piston is movably inserted into a cylinder hole so as to define a hydraulic pressure chamber between the piston and a cylinder hole bottom portion. A valve and a valve stem are provided so as to protrude from a distal end of the piston to the hydraulic pressure chamber. A fluid passage is formed in a cylinder body so as to communicate with the hydraulic hole and a reservoir. A through hole is formed in the piston so that the fluid passage and the hydraulic pressure chamber communicate with each other. When a brake is operated, the valve closes the through hole with forward movement of the piston to thereby generate a hydraulic pressure in the hydraulic pressure chamber.